Metallurgical Supplies came up with a cheap inspection tool that's able to give you measurements for angle, diameter, and depth.  The system it uses is always calibrated and will never lose its permanent calibration.   This unit can easily mount to any cell phone you have with a camera or a digital camera.

The images you see where taken with an Android & iPhone camera.  As you can see, you can barely tell which was taken with what phone system.  This system is very cost effective, quick go no go system.  No need for an expensive microscope system.  This a great tool when your lab is doing constant notches.